dihedral depends on where you place the wing, low down you need some, mid wing none. I would go mid wing, fairly thick fully symmetrical section, (better for 3D and constant speed aerobatics) double taper, no washout, slightly thicker section at the tips. Tailplane slightly above wing, 25% of wing area, fin and rudder 14% of wing area, I would build the nose extra long and at the last minute cut it back to balance the plane at about 33% of the root cord. 30% if you want more pattern type flying. Make sure your body has enough depth for KE. wing and body the same length.

The main thing is too keep it as light as possible.